Question

Which of the following is an irrational number?
a 9 squared
b 84 squared
c 1.7
d 64 squared

Answer 1

I'm assuming you meant to say \[\Large \sqrt{9}\] for choice A and similar for B & D

Answer 2

you'd be correct then

Answer 3

if you take the square root of a positive whole number and you get a whole number, then that original number is rational. Otherwise, it's irrational

Answer 4

example

\[\Large \sqrt{16} = 4\]

so that is rational

Answer 5

\[\Large \sqrt{23} \approx 4.79583\] (the decimals go on forever with no pattern) so that is irrational

Answer 6

so how would i solve this problem for example how should i divide it

Answer 7

take the square root of the stuff under the square root symbol

and use the rule I mentioned above

Answer 8

ok

Answer 9

so then 84 is the correct answer then right?

Answer 10

?

Answer 11

yes because \[\Large \sqrt{84} \approx 9.16515\] while the other roots are whole numbers

Answer 12

the 1.7 is not irrational because you can say 1.7 = 17/10